The invention relates to methods and apparatuses useful in dispensing fluids, especially as applied to high precision process chemical delivery and flow control, and especially but not exclusively with applications for dispensing process fluids in microelectronic device processing.
Various commercial and industrial processes involve flow control, pumping, or dispensing of fluids, often requiring or with benefit from high precision. An example is processing of microelectronic devices, which are processed to be cleaned, coated, and recycled. These processing steps can involve dispensing onto a substrate a fluid such as a photoresist material, a developer, a spin-on dielectric material, an etchant, a solvent, a cleanser, water, or another useful fluid. The microelectronic device substrate may include a semiconductor material or assembly, a thin-film xe2x80x9cread-writexe2x80x9d head, a flat panel display substrate, a fiber optic modulator substrate, or similar known microelectronic devices.
For many reasons, some of which may relate to cost, quality control, uniformity, or general manufacturing efficiency, it can be desirable in many specific applications to precisely control the amount of a fluid applied to a substrate. For example, in spin-coating microelectronic devices, application of a precisely accurate amount of a photoresist material and/or a subsequent developing solution can result in highly accurate and uniform thicknesses of each applied material, allowing very high uniformity of the photoresist and developer coatings, and ultimately allowing quality and consistency in a microelectronic device produced. A different motivation for precise control of a volume of fluid could be where a fluid is a cost-expensive component of a process, such as can also be the case for photoresist materials and other materials involved in processing microelectronic devices.
Industry continues to search for new methods and equipment that offer improved ability to dispense fluids, especially with very accurate and precise volume control.
The invention relates generally to apparatuses and methods for dispensing fluids. The apparatuses can be useful for dispensing any type of fluids, but may be particularly useful for applying processing fluids to microelectronic devices, especially with semiconductor wafer substrates. The methods and apparatuses relate in general to the use of fluid pressure differentials (e.g., pressure and vacuum) to control the direction and amounts of fluid flow through a chamber by changing the volume of the chamber, e.g., by expanding and compressing the chamber, in combination with opening and closing inlets and outlets of the chamber, preferably allowing for high precision control of the flow of fluid. xe2x80x9cHigh precisionxe2x80x9d dispensing means that an actual volume of dispensed fluid will be within one percent of a targeted volume.
An apparatus of the invention can include a process chamber at least partially enclosed by a control chamber. The volume of the process chamber can be controlled by adding and removing control fluid to and from the control chamber. An inlet of the process chamber can be connected through a valve to a process fluid reservoir, and an outlet of the process chamber can be connected through a valve to a location of dispense such as a microelectronic device manufacturing apparatus.
An apparatus of the invention can be used to cause flow of a fluid into and out of the process chamber for dispensing, by controlling each of the input and output valves in combination with the volume of the process chamber. Fluid can be drawn into the process chamber through the input valve while the input valve is opened and the outlet valve is closed, and fluid can be expelled from the process chamber while the inlet valve is closed and the outlet valve is opened. The volume of the process chamber can be controlled (i.e., increased and decreased while the valves are opened and closed) by controlling the volume and/or pressure of control fluid in the control chamber, e.g., by adding and removing control fluid to and from the control chamber, or by otherwise increasing and decreasing the pressure inside the control chamber.
One embodiment of an apparatus of the invention can be used to dispense various different process fluids from a single apparatus, by including multiple process chambers connected to different (or the same) fluids, the different process chambers being enclosed in a single control chamber and each being independently valved at an outlet and an inlet.
The fluid dispensed can be any useful fluid, especially a processing fluid, and especially where precise control of the amount of fluid dispensed is desired. Exemplary process fluids for use with the apparatus and methods in the context of processing a microelectronic device include photoresists, developers, solvents, cleaners, water, and other useful processing solutions and fluids, and mixtures thereof.
An aspect of the invention relates to an apparatus for dispensing a fluid to a microelectronic device. The apparatus includes a process chamber enclosed by a control chamber. The inlet of the process chamber can connect to a fluid reservoir. The outlet of the process chamber can connect to a microelectronic device manufacturing apparatus. The volume of the process chamber can be controlled by an amount or pressure of control fluid in the control chamber.
Another aspect of the invention relates to an apparatus for dispensing two or more fluids. The apparatus comprises two or more process chambers inside of one control chamber. Each process chamber includes a fluid input connected to a valve and a fluid output connected to a valve. The volume of each process chamber can be controlled by an amount or pressure of control fluid in the control chamber.
Yet another aspect of the invention relates to a method of dispensing a process fluid in processing a microelectronic device. The method includes providing an apparatus for dispensing a process fluid to a microelectronic device, the apparatus including a process chamber enclosed by a control chamber. An inlet of the process chamber can be connected through a valve to a fluid reservoir. An outlet of the process chamber can be connected through a valve to a microelectronic device manufacturing apparatus. The volume of the process chamber can be controlled by an amount of control fluid added to and removed from the control chamber.
Yet another aspect of the invention relates to a method of dispensing multiple fluids. The method includes providing an apparatus comprising two or more process chambers inside of one control chamber. Each process chamber has a fluid input connected to a valve and a fluid output connected to a valve. A volume of each process chamber can be controlled by an amount or pressure of control fluid in the control chamber.